Búsqueda Imágenes Maps Play YouTube Noticias Gmail Drive Más »
Iniciar sesión
Usuarios de lectores de pantalla: deben hacer clic en este enlace para utilizar el modo de accesibilidad. Este modo tiene las mismas funciones esenciales pero funciona mejor con el lector.

Patentes

  1. Búsqueda avanzada de patentes
Número de publicaciónUS6212883 B1
Tipo de publicaciónConcesión
Número de solicitudUS 09/518,409
Fecha de publicación10 Abr 2001
Fecha de presentación3 Mar 2000
Fecha de prioridad3 Mar 2000
TarifaCaducada
Número de publicación09518409, 518409, US 6212883 B1, US 6212883B1, US-B1-6212883, US6212883 B1, US6212883B1
InventoresHan-Yong Kang
Cesionario originalMoon-Ki Cho
Exportar citaBiBTeX, EndNote, RefMan
Enlaces externos: USPTO, Cesión de USPTO, Espacenet
Method and apparatus for treating exhaust gas from vehicles
US 6212883 B1
Resumen
A method and apparatus for treating exhaust gas produced from the combustion of fuels is disclosed. Pollutants such as unburnt hydrocarbons, carbon monoxides, oxides of nitrogen and oxides of sulfur are oxidized by ozone in an ozone contractor, and then resolved by water vapor in a muffler, so that they can be reduced.
Imágenes(2)
Previous page
Next page
Reclamaciones(9)
What is claimed is:
1. A method for treating exhaust gas produced from the combustion of fuels, comprising:
introducing ozone into the exhaust gas in an ozone contactor which is located downstream of a catalytic converter;
passing the exhaust gas through a muffler having an inlet and an outlet;
introducing water vapor into the exhaust gas prior to the outlet of the muffler; and
passing the exhaust gas through at least a portion of a muffler, thereby reducing at least one pollutant, selected from a group consisting of unburnt hydrocarbons, carbon monoxide and oxides of nitrogen, from a first concentration to a second lower concentration.
2. The method of claim 1, further comprising the step of:
producing ozone in the amount of 3 grams per hour at a fixed frequency of 600 Hz in a corona discharge type ozone generator.
3. The method of claim 2, wherein the ozone is generated from air which passes through an air filter.
4. The method of claim 1, further comprising the step of:
producing water vapor with a water evaporator which has the ratio of condensate water:water vapor=4:1.
5. An apparatus for treating exhaust gases produced from the combustion of fuels, comprising:
an ozone contactor located downstream from a catalytic converter, for mixing the exhaust gas with ozone;
a muffler having an inlet and an outlet;
a water evaporator for adding water vapor to the exhaust gas; and
a passageway for conducting water vapor into the muffler such that the exhaust gas stream passes through water vapor prior to exhausting from the outlet of the muffler.
6. The apparatus of claim 5, further comprising
an ozone generator for producing ozone from air which passes through an air filter.
7. The apparatus of claim 5, wherein the ozone generator is a corona discharge type.
8. The apparatus of claim 7, wherein the ozone is produced in an amount of 3 grams per hour at a fixed frequency of 600 Hz.
9. The apparatus of claim 5, wherein the water evaporator produces water vapor which has a ratio of condensate water:water vapor=4:1.
Descripción
BACKGROUND OF THE INVENTION

(a) Field of the Invention

The present invention relates to a method and apparatus for treating exhaust gas produced from the combustion of fuels, and more particularly, to such a method and apparatus wherein the reduction of pollutants is achieved by the use of ozone and water vapor.

(b) Description of the Related Art

Internal combustion engines, which operate by the controlled combustion of hydrocarbon fuels, produce exhaust gases containing the complete combustion products of CO2 and H2O, and also pollutants from incomplete combustion, such as unburnt hydrocarbons (HC) as well as CO, which is a direct poison to human life. Further, due to the very high temperatures produced by the burning of hydrocarbon fuels, thermal fixation of nitrogen from the air results in the detrimental formation of nitric oxides (NOx).

The quantity of pollutants varies with many operating conditions of the engine, but it is influenced predominantly by the air-to-fuel ratio in the combustion chamber. Conditions conducive to reducing carbon monoxide and unburnt hydrocarbons (a fuel mixture just lean of stoichiometric as well as high combustion temperatures) cause an increased formation of NOx, and conditions conducive to reducing the formation of NOx (rich fuel mixture and low combustion temperatures) cause an increase in carbon monoxide and unburnt hydrocarbons in the exhaust gases of the engine. As a result, within the region of stable operation of the internal combustion engine, a significant amount of CO, HC and NOx is emitted into the atmosphere.

There has been a proposed three-way catalysis (TWC) technology to reduce the pollutants of the exhaust gases. The TWC technology comprises the use of precious metals Pt, Rh, and Ce. The basic operation of Pt is to oxidize CO and HC to CO2 and H2O, Rh is primarily responsible for the reduction of NOx, and Ce functions as an emitter of oxygen. The activity of Rh, however, is reduced in a high oxidizing atmosphere, and Rh may react with CeO2 at high temperature, reducing the activity of both.

Reduction technology has also proposed the use of ammonia as a reducing agent and V2O5—TiO2 as a catalyst, but this is likely to exhaust toxic ammonia gas according to the concentration of NOx in the exhaust gas.

Another reducing agent has been proposed using hydrocarbons instead of ammonia in Japanese Laid-Open Patent Application No. 63-100919. A catalyst is used in combination with copper and a porous carrier such as alumina, silica or zeolite. However, this method has drawbacks in that the catalyst is likely to be degraded by SOx.

SUMMARY OF THE INVENTION

In view of the prior art described above, it is an object of the present invention to provide a method and apparatus for treating exhaust gas produced from the combustion of fuels.

It is another object of the present invention to provide a method and apparatus for reducing pollutants of incomplete combustion in the exhaust gases treated by the use of ozone and water vapor.

A particularly advantageous feature of preferred embodiments of the present invention is that they can be applied to a variety of different types of internal combustion engines, including, but not limited to, automobiles, trucks, stationary power generators, motor boats and motorcycles.

To achieve these and other objects and features, as embodied and broadly described herein, the invention comprises the steps of:

introducing ozone into the exhaust gas in an ozone contactor which is located downstream from a catalytic converter;

passing the exhaust gas through a muffler having an inlet and an outlet;

introducing water vapor into the exhaust gas prior to the outlet of the muffler; and

passing the exhaust gas through at least a portion of a muffler, thereby reducing at least one pollutant, selected from the group consisting of unburnt hydrocarbons, carbon monoxide and oxides of nitrogen, from a first concentration to a second lower concentration.

According to another aspect of the present invention, an apparatus for treating exhaust gas produced from the combustion of fuels, comprising:

an ozone contactor located downstream from a catalytic converter, for mixing the exhaust gas with ozone;

a muffler having an inlet and an outlet;

a water evaporator for adding water vapor to the exhaust gas; and

a passageway for conducting water vapor into the muffler such that the exhaust gas stream passes through water vapor prior to exhausting from the outlet of the muffler.

Both the foregoing general description and the following Detailed Description are exemplary and are intended to provide further explanation of the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings provide a further understanding of the invention and, together with the Detailed Description, explain the principles of the invention. In the drawings:

FIG. 1 is a block diagram illustrating an embodiment of the apparatus of the present invention; and

FIG. 2 is a block diagram illustrating the method of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention will be described in detail with reference to the accompanying drawings.

Referring to FIG. 1, one embodiment of an apparatus of the present invention is illustrated generally at 10. The apparatus 10 comprises an ozone contactor 5, ozone generator 2, water evaporator 3 and muffler 6. The ozone contactor 5 is located upstream from a muffler 6 and downstream from a catalytic converter 4. The ozone generator 2 provides the ozone contactor with ozone.

The ozone generator 2 can be either of two basic types: ultraviolet or corona discharge. The ultraviolet type employs gas-discharge lamps which emit bright ultraviolet light (also called “UV” or “black light” lamps) which breaks up atmospheric oxygen and thus creates ozone. Because UV lamps are relatively fragile and bulky, requiring a large housing in ultra-violet type ozone generators, corona discharge type generators are preferably used in the embodiment of the present invention.

The ozone generator 2 of the corona discharge type creates ozone by subjecting air, which is provided from an air filter 1, to a very high electric field. The strong electric field sufficient to break up oxygen molecules is supplied from an inverter, which comprises insulated gate bipolar transistors (IGBT) and a transformer having a winding ratio of 1:10. The high-voltage coil of the inverter is connected to two electrodes such that one goes positive when the other is negative. The two electrodes form a sort of capacitor, and usually comprise two parallel plates, concentric cylinders, or some other geometry which allows for a constant distance between the electrodes. The description of the ozone generator 2 may also be modified to explain similar structures, and further descriptions thereof will not be made.

The ozone generator 2 preferably produces ozone in the amount of 3 grams per hour at 600 Hz, the fixed frequency of the inverter.

The water evaporator 3 may include a vibrator in the form of an electrically operable ultrasonic transducer. The water is made to vibrate by a high-frequency vibrator which causes the water to be atomized. An air stream directed onto the water carries the water vapor into the muffler 6. The water evaporator 3 preferably produces water vapor which has the ratio of condensate water: water vapor=4:1.

The muffler 6 has an inlet and outlet for the exhaust gas stream. A passageway is provided for conducting water vapor produced from the water evaporator 3 into the muffler 6 such that the exhaust gas stream passes through the water vapor prior to exhausting from the outlet of the muffler.

Referring now to FIG. 2, the method of the present invention is illustrated.

The exhaust gas stream, which is already treated by the catalytic converter 4 at a temperature of 300-400° C., enters the ozone contactor 5. In the ozone contactor 5, the exhaust gases are mixed with ozone produced by the ozone generator 2 (Step S1). In this step S1, pollutants comprising unburnt hydrocarbons (HC), NOx, and SOx react with ozone and oxidize into CO2, NO3−, and SO3 2−, respectively. Carbon monoxide (CO) may also oxidize into CO2.

Next, the gas stream passes through the muffler 6 in which water vapor is introduced (Step S2). At least one pollutant in the gas reacts with the water vapor to reduce the pollutants. Specifically, NO3− and S0 3 2− react with the water and turn into HNO3 and H2SO4, respectively. Because HNO3 and H2SO4 are in liquid phase, they are easy to separate from the gas. Accordingly so that the resultant exhaust gas expelled by the muffler 6 is primarily CO2, and the other pollutants are reduced (Step S3).

Table 1 compares the results obtained with and without the apparatus according to the present invention.

TABLE 1
Without the With the present
Reference criteria present invention invention
CO 4.5% 7.4% 0
HC Below 220 ppm 310 ppm 17 ppm
NOX 35% 47% Below 6%
SOX 35% 45% Below 6%

As shown in Table 1, pollutants comprising CO and HC to CO2 and SO2 are remarkably reduced.

It will be apparent to those skilled in the art that various modifications and variations can be made to the device of the present invention without departing from the spirit and scope of the invention. The present invention covers the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.

Citas de patentes
Patente citada Fecha de presentación Fecha de publicación Solicitante Título
US3984296 *13 Sep 19745 Oct 1976Richards John RPhotochemical
US4945721 *14 Abr 19887 Ago 1990Environmental Research International, Inc.Electromagnetic converter for reduction of exhaust emissions
US5121602 *26 Dic 199016 Jun 1992Mccorvey Allan FPollution control apparatus
US5223105 *29 Jun 199029 Jun 1993Arthurson Corporation Pty. Ltd.Ultraviolet lamp, means to direct flow of oxygen-containing gas through zone of exposure to ultraviolet radiation and high voltage, low current electric field
US5806305 *28 Jun 199615 Sep 1998Lockheed Martin CorporationMethod for improving the conversion efficiency of a catalytic converter
US5807526 *14 Oct 199415 Sep 1998Miljevic; VujoDevice for removal of SO2 and NOx from flue gases by high frequency discharge by Tesla coil or other high voltage and high frequency generator
US5863413 *18 Dic 199626 Ene 1999Litex, Inc.Supplying remotely generated hydroxy radicals to pre- or postcombustion gas flows for oxidation of exhaust gases within catalytic converter
US6012283 *23 Jun 199811 Ene 2000Lockheed Martin Corp.Method and apparatus for reducing pollutants
US6033462 *30 Jun 19987 Mar 2000Dekker Vacuum Technologies, Inc.Oil seal system
US6038853 *15 Jul 199821 Mar 2000The Regents Of The University Of CaliforniaPlasma-assisted catalytic storage reduction system
US6038854 *22 Jul 199821 Mar 2000The Regents Of The University Of CaliforniaPlasma regenerated particulate trap and NOx reduction system
US6047543 *24 Jul 199811 Abr 2000Litex, Inc.Method and apparatus for enhancing the rate and efficiency of gas phase reactions
US6048500 *6 Mar 199811 Abr 2000Litex, Inc.Method and apparatus for using hydroxyl to reduce pollutants in the exhaust gases from the combustion of a fuel
US6153151 *5 Ago 199928 Nov 2000Moxley; Douglas A.System and method for generating ozonated water
DE4231581A1 *21 Sep 199224 Mar 1994Siemens AgVerfahren zur plasmachemischen Zersetzung und/oder Vernichtung von Schadstoffen, insbesondere zur Abgasreinigung von Verbrennungsmotoren oder anderer mit fossilem Treibstoff betriebenen Maschinen, sowie zugehörige Vorrichtung
JPS5870016A * Título no disponible
JPS63100919A Título no disponible
Citada por
Patente citante Fecha de presentación Fecha de publicación Solicitante Título
US654448529 Ene 20018 Abr 2003Sharper Image CorporationElectro-kinetic device with enhanced anti-microorganism capability
US658593520 Nov 19981 Jul 2003Sharper Image CorporationElectro-kinetic ion emitting footwear sanitizer
US65884342 Jul 20028 Jul 2003Sharper Image CorporationIon emitting grooming brush
US663240725 Sep 200014 Oct 2003Sharper Image CorporationSelf-contained ion generator that provides electro-kinetically moved air with ions and safe amounts of ozone
US667231519 Dic 20006 Ene 2004Sharper Image CorporationIon emitting grooming brush
US6682707 *14 Nov 200127 Ene 2004Kiwi Auto Accessories Co., Ltd.Exterior hood; electrode layout connecting by cable
US6684629 *1 Oct 20023 Feb 2004Siemens AktiengesellschaftMethod for checking the conversion capacity of a catalytic element for converting ozone
US67094848 Ago 200123 Mar 2004Sharper Image CorporationElectrode self-cleaning mechanism for electro-kinetic air transporter conditioner devices
US67130265 Dic 200030 Mar 2004Sharper Image CorporationElectro-kinetic air transporter-conditioner
US674966721 Oct 200215 Jun 2004Sharper Image CorporationElectrode self-cleaning mechanism for electro-kinetic air transporter-conditioner devices
US68270884 Jun 20037 Dic 2004Sharper Image CorporationIon emitting brush
US6912841 *10 Jul 20025 Jul 2005Robert Bosch GmbhTreating the exhaust gas of an internal combustion engine are proposed, comprising an ozone reactor for supplying ozone to the exhaust gas at a delivery location, an oxidation reactor for the at least partial oxidation of nitrogen oxides and/or
US6948308 *18 Feb 200327 Sep 2005Johnson Matthey Public Limited Companyozone is reacted with nitrogen monoxide to form nitrogen dioxide, which is then reduced catalytically to nitrogen
US695813412 Feb 200225 Oct 2005Sharper Image CorporationUsed for generating an electrical potential between a first electrode and a second electrode in order to create a flow of air in downstream direction from first to second electrode and to ionize particle matter in airflow; a focus electrode
US8051643 *12 Jun 20068 Nov 2011Toyota Jidosha Kabushiki KaishaExhaust gas purification system utilizing ozone
US8066851 *23 Oct 200729 Nov 2011M-I L.L.C.In-line treatment of hydrocarbon fluids with ozone
US8266895 *11 Abr 200818 Sep 2012Toyota Jidosha Kabushiki KaishaO3 production apparatus and exhaust gas purification system for internal combustion engine
US20090184050 *17 Ene 200823 Jul 2009Barr Dale CSystems and Methods for Watercraft Having Marine Environment Enhancement Capability
US20100064669 *11 Abr 200818 Mar 2010Toyota Jidosha Kabushiki KaishaO3 production apparatus and exhaust gas purification system for internal combustion engine
US20100132337 *11 Mar 20083 Jun 2010Hirohito HirataExhaust gas purification device for internal combustion engine
US20100275586 *28 Nov 20064 Nov 2010Hirohito HirataDevice for cleaning exhaust gas of internal combustion engine
EP1712752A2 *21 Mar 200618 Oct 2006Toyota Jidosha Kabushiki KaishaExhaust gas purifying apparatus and method thereof
Clasificaciones
Clasificación de EE.UU.60/275, 204/176, 60/310, 422/186.07
Clasificación internacionalF01N13/02, F01N3/08, F01N3/28, F01N3/20
Clasificación cooperativaF01N3/0892, F01N2430/04, F01N3/206, F01N3/2882, F01N13/009, F01N2240/38
Clasificación europeaF01N3/28D, F01N3/08C, F01N3/20D
Eventos legales
FechaCódigoEventoDescripción
28 May 2013FPExpired due to failure to pay maintenance fee
Effective date: 20130410
10 Abr 2013LAPSLapse for failure to pay maintenance fees
19 Nov 2012REMIMaintenance fee reminder mailed
30 Sep 2008FPAYFee payment
Year of fee payment: 8
30 Sep 2004FPAYFee payment
Year of fee payment: 4
3 Mar 2000ASAssignment
Owner name: CHO, MOON-KI, KOREA, REPUBLIC OF
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:KANG, HAN-YONG;REEL/FRAME:010658/0548
Effective date: 20000217
Owner name: CHO, MOON-KI 45-6, NAMSANDONG 3-GA JOONG-KU SEOUL